I have a 01' chevy blazer and I had just got the fuel pump replaced and there is a weird popping sound coming inside the tank whenever i turn it off, can any one help me. thanks

 

Surprised that Admin Swartlkk didn't jump all in here - it's a popular problem. I have been reading up on said problem for my own truck: did you find a solution? If so, was it the vent valve, or the enigmatic carbon module? If not, have you tried those yet?